This invention relates to sheet materials with adhesives used in making, for example, covered foam products.
Automobile seat cushions and other foam products are typically produced by a foam-in-place process in which the seat cushion is chemically foamed against a finish fabric covering the seat. The process often begins by first laminating a lubricant-free urethane barrier layer to the finish fabric by, for example, flame lamination. A thin layer of foam placed between the fabric and the barrier layer acts as an adhesive bonding the fabric to the barrier. The resulting tri-layer fabric/foam/barrier composite is then cut and sewn into a sock cushion.
Often, the finished seat is sewn together from several different pieces of finish fabric and the seams of the sock cushion are sealed prior to foaming to prevent liquid components in the foaming process from bleeding through the finish fabrics and to assure a good vacuum barrier during the process of molding the foam cushion.
For ease of handling in cutting and sewing the composite, a slip sheet may be bonded to a surface of the barrier, e.g., a polyethylene sheet heat bonded to the barrier to provide a slippery surface that prevents the composite from catching under the presser foot of a sewing machine.
Use of a pin-hole free urethane film is also discussed in U.S. patent application Ser. No. 07/904,157, filed on Jun. 25, 1992, now abandoned.